This type of locking device is known from DE 3,503,466 C2, which concerns a locking device for a door in which the main lock is designed as a connecting rod lock with a connecting rod which is connected to the bolt-operating device. The connecting rod is used, on the one hand, to mechanically connect the main lock with at least one auxiliary lock which is separate from the main lock, and each of which has one auxiliary bolt. Because the main lock is connected with at least one auxiliary lock by means of the connecting rod, on operation of the bolt of the main lock, the auxiliary bolt(s) is/are also operated from the main lock by means of a key. Therefore, when the bolt of the main lock is slid out, the auxiliary bolt of at least one auxiliary lock is also slid out (with corresponding displacement of the connecting rod in one direction), and when the bolt of the main lock is retracted, the auxiliary bolt of at least one auxiliary lock is correspondingly retracted (with displacement of the connecting rod in the opposite direction).
The leaf-restraining device of the known locking device, also referred to in the following as a door-restraining device, has a handle with which the driving pin can only be moved back and forth between the release position and the driving position from the inside of the door, and with which, in the present case, it can be retracted and/or slid out.
With the driving pin positioned in the driving position, it would be possible to open the door from outside only up to the maximum possible gap position of the leaf, unless a means were provided for moving the driving pin into the release position from the outside of the door. So that the driving pin can be moved from the locked position into the driving position from the outside of the door, and so that the door can therefore be completely opened from the outside as well, in the known locking device, the door-restraining device is connected to the main lock via the connecting rod, which is also provided in order to connect at least one auxiliary lock to the main lock. For this purpose, the connecting rod has a cam which is attached to the connecting rod in the area of the door-restraining device, which is positioned on one side of the driving pin in a first position when the bolt is retracted and on the other side of the driving pin in a second position when the bolt is slid out. When the bolt is slid out or retracted, the cam is therefore moved between the first and second position. When the driving pin is positioned in the driving position, the cam cooperates with an adjoint piece on the driving pin and moves the driving pin into the release position during its movement between the first and second position, i.e., retracts it into the door-restraining device.
The above explanations clearly show that in order to move the driving pin from the driving position to the release position, it is necessary to close the main lock in order to slide the bolt in or out. If the driving pin is in the driving position, but the bolt has not been slid out, the bolt must first be slid out in order to operate the driving pin by means of the locking element and/or key from the main lock, i.e., the locking device must be closed so that the cam on the connecting rod passes the driving pin and thus moves the driving pin into the release position. Now, however, the locking device is closed, and it must again be opened, i.e., the bolt must also be retracted again.
In this configuration, therefore, a complete locking cycle is required in order, from the main lock, to move the driving pin from the driving position to the release position by means of the locking element. This considerably impairs the normal procedure of opening a door by means of a lock, etc., from outside, because one ordinarily simply inserts the key into the lock and turns it in the opening direction until the latch is retracted, and before this, if applicable, the bolt must be pulled in before the door can be opened. In the above-described configuration, one must first turn the key in the locking direction in order to move the driving pin into the release position, and only then can one turn it in the ordinary opening direction in order to open the door. From an ergonomic standpoint, the above-described procedure is extremely unfavorable in opening the door from the outside. The configuration described below also clearly shows that the known locking device is ergonomically unfavorable, such that a situation can easily arise in which improper operation of the locking device adversely affects security.
Let us assume that a person wishes to open an apartment door equipped with the known locking device, wishing to open the door only slightly, keeping it secured with the door-restraining device, for example, because someone unknown to the person has rung the doorbell. In this case, the person will move the driving pin to the driving position by means of corresponding operation of the door-restraining device. Provided that the door is not bolted, the door can now be opened by operating the door handle, etc., in order to operate the latch, and the door is secured by means of the door-restraining device against opening farther than the maximum possible gap position. However, if the door is bolted, i.e., if the bolt of the main lock has been slid out, one must first unbolt the door in order to open it, i.e., retract the bolt. In doing so, however, the driving pin is again placed in the release position. The door can now be freely opened if the latch is operated. In order to restore the security function of the door-restraining device, the person must therefore reset the door-restraining device so that the driving pin is again placed in the driving position. However, a person may easily forget to reset the door-restraining device. On many occasions, the very persons who have a particular requirement for the protection afforded by the door-restraining device, such as children or elderly people, may find it too difficult to operate the known locking device in the proper manner in order to provide sufficient security.
Another possibility of faulty operation in the case of the known locking device should be mentioned. It is possible that a person who wishes to open the door only slightly may attempt to keep the driving pin in the driving position by correspondingly holding a handle, knob, etc., of the door-restraining device in place, while this person, if necessary, unbolts the door, i.e., retracts the bolt of the main lock. However, if the driving pin is held in the driving position, the connecting rod is also blocked from being moved in the unbolting direction, because the cam must pass by the driving pin. This makes it either impossible or very difficult to unbolt the door against the force exerted on the handle of the door-restraining device.
The above examples clearly show that the known locking device is extremely disadvantageous from an ergonomic standpoint and that it allows the possibility of erroneous operation which may seriously impair security.
The object of the invention is to provide a locking device of the aforementioned type which can be operated in an ergonomically favorable manner and which largely eliminates any possibility of erroneous operation which would impair security. In order to achieve this object, in the invention, the driving pin can only be moved from the driving position to the release position from the main lock by operating the latch by means of the locking element.